Carbonizing compound and process of making and using it



Oct. 23, 1923.

s. B. MATHEWSON ET AL CARBONIZING COMPOUND AND PROCESS OF MAKING AND USING IT Filed April 3, 1922 Patented cars, 1923.

UNITED STATES PATENT OFFICE.

STANLEY B. MATHEWSON AND WALTER K. JAMISON, OF SPRINGFIELD, OHIO, AS-

SIGNORS TO WALTER K. JAMISON, STANLEY B..MATHEWSON, HOWARD F. STON, MRS. W. K. JAMISON, AND MRS. S. B. MATHEWSON, TRUSTEES OF THE LECAR CARBON COMPANY, A TRUST ESTATE.

CARBONIZING COMPOUND ANDTROCESS OF MAKING AND USING IT.

Application filed April 8,

To all whom it may concern:

Be it known that we, STANLEY- B. MATHEWSON and WALTER K. JAMISON, citizens of the United States, residing at Springfield, in the county of Clark and State of Ohio, have invented certain new and useful Improvements in Carbonizing Compounds and Processes of Making and our invention is to utilize scrap leather. by

the treatment of our invention hereinafter described and claimed.

An additional object of our invention is to provide a new product by this treatment which may be utilized as a carbonizing material.

with the scrap leather in order to re uce it to the form of the product now in question; Fig.3 is a diagrammatic view of the rolls and screen for determining the size and grade of the resulting carbonized product; Fig. 4 is an end elevation of a piece of steel before treatment with this carbonizing material;

Fig. 5 is a similar view after carbonization showing the case;

Fig. 6 is a section of a carbonizlng b ox packed with the carbonizing material 1nvolved herein showing the articles being carbonized and the arrangement of their packlIl It will be understood that the foregoing drawings are diagrammatic merely and are only for the purpose of illustration.

Referring to the drawings in detail, 1 1s a carbonizing can or metal container having a tilation therefor.

1922. Serial 1%. 549,274.

lid 2 with apertures 3in the lid thereof. The scrap leather is placed in this can and the can is placed in an oven 4. This oven isheated by any desired means as for instance by burners such as at 5. ,It will be understood that this illustration of the burners is typical only and that any kind of heating apparatus may be employed. The cans are sealed and the lids are tight fitting. The openings 3 are provided in the cans to permit of the adjustment of the internal pressure and to permit of the escape of gases within the container.

The cans are preferably packed in an oil furnace, the temperature of which has been brought up to 1200 degrees F. at which time the burners are shut off and the furnace sealed with the exception of the regular ven- It is customary to allow the furnace to remain closed for about six hours, after which time the containers can be removed and'the finished product may be removed from each one of the individual containers. It is then crushed between the rollers 6-6 and screened by the screen 7 which is preferably about of a =3" mesh. The purpose of this is to reduce it to a suitable size for carbonizing purposes.

Process of hardening steel.-

The finished product thus secured is used as follows' The parts to be carbonized are thoroughly cleansed in an alkali solution in order to remove all dirt and oil. Any cleansing solution of similar character may be employed. They are then packed in the boxes 8 so that the parts 9 will be arranged .in layers in the carbonizing material 10.

The top of the box is sealed with fire cla as at 11. It is the preferred practice to p ace a layer of thecarbonizing material then a layer of parts separated from one another by the-carbonizing material, alayer of can the temperature brought up to 1700 degrees izing boxes.

In the event the furnace is cold when the boxes are placed therein a proportionately greater time will be necessary to efi'ect the desired result.

The boxes employed are usually about eight and one-half inches in diameter, eleven inches deep and walls about thick. It takes about three hours tobrin a hot furnace up to the temperature of 1 00 degrees, the temperature used for carbonizing.

For instance, in the case of carbonizing, S. A. E. 10-2O steel, it has been .found good practice with this carbonizing material to hold the carbonizing heat at 1700 degrees F. for five hours when packed in a box of the above mentioned dimensions in order to obtain a depth of case.

The preferred method after this temperature has been maintained this desired length of time is 'to allow the case hardened steel parts to cool in the carboni'zing boxes before they are exposed to the air.

We do not desire to confine our invention to any particular type of furnace for the heat treatment. An open type furnace may be employed in which the temperature has been brought up. to 1450 degrees F. before the parts are placed in the furnace. It will then customarily ,require about fifteeen to twenty minutes to bring a a" part, speaking in terms of'diameters, up to 1450 egrees The parts are then removed and uenched in brine or oil. It will be understoo that these parts are always removed from the furnace and quenched on the rising heat.

In the second method a salt bath may be used and the parts are immersed in this solution. After the solution has been brought up to 1450 degrees F. the parts are removed and quenched in brine or oil. This t pe of furnace is usually designated a cyani e furnace. It will be understood that the fire does not 'come in direct contact with the work as acast iron tank is placed in the furnace and the salt solution is placed in the tank and melted by the heat coming in contact with the outside of the tank. 7

It will be further understood that it is preferred by us that all quenching solutions be retained at as low a temperature as possible, which is accomplished by any well known means such as circulating the. solution through cooling-coils.

Referring to Figs. 4 and 5, 12 is a specimen of steel and 13 is the case.

When the carbonizing material so pro- I duced by the above mentioned process is examined with the naked eye it appears to be a porous cellular structure with a highly vitrified appearance. and therethrough are irregular in shape and ElZB.

The carbonaceous material referred to herein as the carbonizing compound is generally composed of approximately 30% to 31% volatile matter, about 3% moisture, about 58% fixed carbon and about 8% ash. It will be understood that these amounts are approximate.

Upon analysis the ash will usually develop a ferric oxide color. The volatile matter consists of various gases. In these gases a varying amount of ammonia will be found and the usual reaction to litmus will be alkaline.

While we have shown and described certain features as constituting our invention, it will be understood that parts have been shown for purposes of illustration only, and that we do not desire to be limited to such details, as obvious modifications will occur to persons skilled in the art.

Having thus fully described our invention, what we claim as new and desire tosecure by Letters Patent, is

1. In a new article of manufacture to be utilized for carbonizing metals, fixed carbon and volatile matter to act as a carrying agent for the carbon into the surface of the metal upon heating in the presence of the metal to be so treated.

2. In a new article of manufacture to be utilized for carbonizing metals characterized by analysis by a fixed carbon, volatile matter, moisture and ash adapted when heated in the presence of metals to a predetermined temperature to carry the carbon through the agency of the volatile matter into the surface of the metal to case harden the metal.

3. A new article of manufacture for case hardening metals containing carbon and volatile matter.

4. In combination in a new article of manufacture for case hardening metal, fixed carbon 58% approximately, volatile matter 31% approximately, moisture 3% approximately, ash 8% approximately.

5. In combination in a new article of manufacture for case hardening metal. fixed car- The apertures therein I bon 58% approximately, volatile matter- 3l% approximately, moisture 3% approximately, ash 8% approximately, said article having the characteristic that when it is below a predetermined temperature the volatile matter will be held in suspension therein and after being. heated above a predetermined temperature it will be released in the form of a gas having the characteristics of being inflammable, ammoniacal in odor and alkaline to litmus:

6. In combination in a new article of manufacture for case hardening metal fixed carbon, volatile matter, moisture and ash, said article having the characteristic that when m it is below a predetermined temperature the volatile matter will be held in suspension therein and after'being heated above a predetermined temperature it will be released in 5 the form ofa gas having the characteristics of being inflammable, annnoniacal in odor and alkaline t0 litmus.

7 In combination in a new article of manufacture for case hardening metal, fixed-carbon, volatile matter, and moisture.

In testimony whereof, We aifix our signatures.

STANLEY B. MATHEWSON. WALTER K. JAMISON. 

